diff --git a/minillmflow/__init__.py b/minillmflow/__init__.py
index 79250b5..eecd859 100644
--- a/minillmflow/__init__.py
+++ b/minillmflow/__init__.py
@@ -57,7 +57,7 @@ class Flow(BaseFlow):
             curr.set_params(p)
             c = curr._run(shared)
             curr = self.get_next_node(curr, c)
-    def exec(self, shared, prep_res): raise NotImplementedError("Flow exec not used directly")
+    def exec(self, shared, prep_res): raise NotImplementedError
 
 class BaseBatchFlow(BaseFlow):
     def prep(self, shared): return []
@@ -65,9 +65,10 @@ class BaseBatchFlow(BaseFlow):
 class BatchFlow(BaseBatchFlow, Flow):
     def _run(self, shared):
         prep_res = self.prep(shared)
-        for d in prep_res:
-            mp = self.params.copy(); mp.update(d)
-            self._exec(shared, mp)
+        for batch_params in prep_res:
+            flow_params = self.params.copy()
+            flow_params.update(batch_params)
+            self._exec(shared, flow_params)
         return self.post(shared, prep_res, None)
 
 class AsyncNode(Node):
@@ -88,7 +89,7 @@ class AsyncFlow(BaseFlow, AsyncNode):
         curr, p = self.start_node, (params if params else self.params.copy())
         while curr:
             curr.set_params(p)
-            c = await curr._run_async(shared) if hasattr(curr, "run_async") else curr._run(shared)
+            c = (await curr._run_async(shared) if hasattr(curr, "run_async") else curr._run(shared))
             curr = self.get_next_node(curr, c)
     async def _run_async(self, shared):
         prep_res = self.prep(shared)
@@ -98,7 +99,8 @@ class AsyncFlow(BaseFlow, AsyncNode):
 class BatchAsyncFlow(BaseBatchFlow, AsyncFlow):
     async def _run_async(self, shared):
         prep_res = self.prep(shared)
-        for d in prep_res:
-            mp = self.params.copy(); mp.update(d)
-            await self._exec_async(shared, mp)
+        for batch_params in prep_res:
+            flow_params = self.params.copy()
+            flow_params.update(batch_params)
+            await self._exec_async(shared, flow_params)
         return await self.post_async(shared, prep_res, None)
\ No newline at end of file